/*
 * Copyright 2016-2019 yoara
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package yhao.infra.feature.oracle.mybatis.dialect;

import yhao.infra.service.datasource.mybatis.dialect.Dialect;

/**
 * Oracle分页实现
 *
 * @author yoara
 */
public class OracleDialect extends Dialect {
	public boolean supportsLimitOffset(){
		return true;
	}
	
    public boolean supportsLimit() {   
        return true;   
    }  
    
	public String getPageString(String sql, int offset, int limit) {
        int limitTo = offset+limit;
        StringBuilder sqlBuilder = new StringBuilder(sql.length() + 120);
        sqlBuilder.append("select * from ( select tmp_page.*, rownum row_id from ( ");
        sqlBuilder.append(sql);
        sqlBuilder.append(" ) tmp_page ")
                .append(" ) where row_id > ").append(offset)
                .append(" and row_id <= ").append(limitTo);
        return sqlBuilder.toString();
	}
}
